Rocket fin



3 Sheets-Sheet 1 June 2, 1964 H. F. HALS-ran Erm.

` ROCKET FIN Filed April 18. 1961 June 2, 1964 H. F. HALsTED :TAL 3,135,203

ROCKET FIN 3 Sheets-Sheet 2 Filed April 18, 1961 June 2, 1964 H. F. HALsTr-:D ETAL 3,135,203

ROCKET FIN Filed April 18, 1961 3 Sheets-Sheet 3 ,2id/Md( UGENT United States Patent 3,135,203 BUCKET HN Hai F. Halsted, .Monrovia, David Benini, Lynnwood, Russell B. Memorie, Los Angeles, and Howard H. Anderson, La Puente, Caiif., assignors to Atlantic Research Corporation, Fairfax County, Va., a corporation of Virginia FiledApr. 18, 1961, Ser. No. 163,849 9 Claims. (Cl. N92-50) The present invention relates in general to rockets, and more particularly to iin assemblies for rocket vehicles and the attachment thereof to the body of the rocket vehicle.

j Heretofore, it has been the customary practice in many types of rocket vehicles to affix fins to the vehicle body by Welding. Specifically, in the case of certain rocket vehicles or rocket booster units, the ns have been customarily formed by Welding together the various components of each fin and then the hns are welded directly to the quadrant assembly structure constituting the structural core orrframe ofV the rocket or booster body. This welding of the components introduced a source of possible undesirable distortion of the fin, such as fin twist, bow and the like, and eliminated the possibility of adjustment of iin incidence setting in the field.

An object of the present invention is the provision of a novel rocket iin assembly construction wherein all Welding is eliminated and which provides improved strength characteristics.

Another object of the present invention is the provision of a novel rocket `iin assembly construction wherein the iins are mounted on the rocket motor case by means permitting adjustment of fin incidence setting in the field.

Another object of the present invention is the provision of a novel rocket iin assembly construction wherein .the fins are attached to a supporting structure which is in turn fastened to the motor unit of a rocket vehicle in a manner permitting adjustment of fin incidence setting in the field.

' Other'objects, advantages and capabilities of the present invention' will become apparent from the following detail description, taken in conjunction with the accompanying drawings, illustrating one preferred embodiment of theV invention.

In the drawings:

FIGURE lf is a side elevation of a iin assembly for rocket vehicles constructed in accordance with the present invention, with parts of the assembly broken away to illustrate the internal construction thereof and illustrating in broken lines a fragmentary portion of the rocket vehicle to which the assembly is to be attached;

FIGURE 2 is a vertical transverse section view taken along the line 2-2 of FIGURE l;

FIGURE 3 is a side elevation of the ring assembly supporting structure for the tins;

FIGURE 4 is a fragmentary section View taken along the line 4-4 of FIGURE l illustrating the means for locking the fins in the ring assembly supporting structure; and

FIGURE 5 is a section view taken along the line 5 5 of FIGURE l illustrating the internal iin construction.

Referring to the drawings wherein like reference characters designate corresponding parts throughout the several figures, the fin assembly of the present invention, indicated generally by the reference character 10, is to be affixed to the aft or trailing portion of a rocket motor, a fragmentary portion of which is shown in broken lines in` FIGURE l and designated by the reference character 1-1, the rocket motor 11 terminating at its trailing end in arocket motor nozzle 12. It will be understood that the n assembly of the present invention may be used 3,135,203 Patented .lune 2, 1964 with a wide variety of rocket vehicles, or booster stages for rocket vehicles, the specific embodiment herein described being illustrated in association with the rocket motor and nozzle portion of a known ground-to-air antiaircraft military rocket missile in the accompanying drawings. l

The iin assembly 10 of this embodiment includes four fins 13 projecting radially from the axis of the rocket motor 11 in quadrature relation, each of the tins 13 being of substantially isosceles trapezoidal profile when viewed from the side thereof and having a root 14'disposed adjacent the rocket motor and a tip 15 of considerably shorter axial dimension than the root 14 spaced outwardly therefrom together with'leading and trailing edges 16 and 17. The fins 13 are each constructed of a center spar casting structure 1S in the form of an integral open network of elongated elements shaped to establish the proper contour of the side surfaces of the iin and including a root plate section 19 and a tip plate section 2i).` The casting structure 18 of each iin is thenV covered with skin panels 21 and 22, each of which is securely fastened to the casting structure 1S by rivets, such as the rivets 23, extending through the elements of the casting structure 1S. The overlapping leading and trailing edge portions of the skin panels 21 and 22 are also secured together with rivets 24. The leading edge 16 is further formed by disposing a rod 25 along the length of the leading edge 16 against the b utting skin panel edges and covering the leading edge with a cap 26 secured by sheet metal screws to the skin panels 21 and 22.

Centrally located at the root 14 of each 'fin 13 is a journal member or stub 27 of somewhat larger diameter than the depth of the hns, the journal member 27 having a cylindrical configuration in which a canted socket 2S is provided in one side thereof having a cylindrical segment surface formed along an axis 29 inclined tothe axis of the journal member 27 at an angle converging in'- Wardly toward the rocket motor axis to intersect the axis of the journal member at some point intermediate the jotunal member' and the rocket motor axis. The root plate section 19 of the casting structure also includes a pair of sockets 30 opening through the inner face of the root section and spaced symmetrically fore andfaft' of the axis of the journal member 27.

The fins 13 are all supported by a' ring assembly supporting structure 31 comprising a pair of axially spaced rings 32 and 33 each formed of a pair of semicircular annular ring sections 34, 35 bolted together at T mounting brackets 36 which are welded to the adjacent portions of the associated ring sections 34, 35 at the ends thereof. rl`he ring sections 34, 35 are each provided with outer and inner circumferential flanges 37, 38 and have bolted to the annular walls 39 thereof at quadrature related points n mounts 4t) which interconnect the rings 32 and 33 and extend parallel to the axis of the rocket motor. Each of these fin mounts 40 have aligned arm portions 41 terminating in flange formations 42 which are bolted flat against the annular Walls 39 of the rings 32, 33 and include an integral journal receiving socket formation 43 centrally located between the flange formations 42. The socket formation 43 has an annular cylindrical Wall 44 surrounding the cylindrical bore 45 and aligned With a radial axis relative to the rocket motor axis for receiving the journal member 27 of one of the fins 13. The bore 45 of the socket formation 43` is open at both ends and is dimensioned to snugly accommodate the journal member 27 of the fins 13. The annular Wall 44 of each socket formation 43 has a boss 46 thereon containing a threaded bore 47 which extends through the boss 46 and wall 44 of each socket formation 43 to threadedly receive a iin restraining screw 48 at a position whereby the inner end of the iin restraining screw 48 will project into the canted Y by mounting screws'SS. a v Y In assembling the iin assembly to the rocket motor 12, the two half Yring assemblies formed'byV the ring 'sections'Y a,

cylindrical segment socket 3V inthe side .ofthe journal member 27 of the associatedn 13 to restrainthe journal.

member against withdrawal from the bore 45 of the socket formation 43. Thearm portions 410i each fin mount 40 are ofhollow construction to minimize weight, and includevr guide holes 49 adjacent each ofthe flange formations 42 for receiving a torque pin 50 and supportingthe sameV l plate sections 19 ofthe associated lin 13; Fin incidence setfscrews 53 having externally accessible heads extend Y through threaded bores in the root plate section 19 of each fin 13 communicating with the sockets 30 whereby the inner ends of the set screws 53 bear against Vtheilats 52 the torque pins 50 to permit adjustmentof the iin incidence before the fin restraining screws 4S are tightened.

A shroud or fairing S4 in the formof a cylindrical tube is provided to be interposedbetween the `ring vassembly supporting structure 31'and the insY 13 inrsurrounding relation to the rocket motor nozzle k12to provide proper aerodynamic characteristics. It will be noted from FIG- AURE 1 that the shroud 54 is provided with a plurality of .screw holes 55 adjacent the leading edge thereof to receive screws for attaching'theshroud 54 to the shoulder 'portion 56 of the rocket motor 11', the shoulder portion 56 being provided with threaded holes with which the screw Y The shroud 54 holes 55 and associated screws register.

is also'provided with suitable apertures for receiving theV journal member 27 and torque pins Sil'therethrough. InV

like manner, the inner circumferential flangesf37 of the ringsV 32, 33 in the ring assembly supporting structure 31l are congurated to lit over theiannular bossesor lands 57 on the rocket motor nozzle 12 and be aixed thereto 34 and 35 of each ring 32, 33 and the fin mounts 40 are placed around the nozzle 12 and positioned to allow the inner circumferential angesS to rest upon the annular' bosses or lands 57 of the rocket nozzlc. The screws are f lmotor nozzle at thegtrailing endllthereof, a assembly comprising a plurality of fins adapted to be rsupportedinV then fitted in the flange portions of the T mounting brackets 36 and adjusted' sutciently tightly to hold the ring half sections together but permit rotation of the ring assembly about the rocket motor nozzle 12. The ring assemblyvis then rotated until holes' in the Ainner circumferential flanges 3S are aligned with corresponding threaded holes in the annular lands 57 and screws are inserted to fix the ring assembly to the rocket motor nozzle` Thescrews interconnecting the T mounting brackets 36 and thescrews g securing the inner circumferential ange 38 to the rocket 'V motor nozzleV are then tightened. TheV shroud S4 is then slid onto therocket motor from. the aft endY and rotated until the screw holes 55 are aligned with the threaded Y holes in the shoulder'portion 56 ofthe rocket motor 11,

and bolts and washers are applied to securely x the shroud to the rocket motor. Thetorque pins 50 are then Y inserted through holes provided Yin the shroud 454 and through the guide holes 49 inthe arm portions 41 of the iin mounts 40, the radially inwardly disposed guide holes i 49 and the inner ends of th'egtorque pins S0 being threaded to permit the torque pins 50 to be securedV in position. I

Thejournal members orstubs 27 ofthe ns 13 are then inserted through the holes provided therefor Vin the' V shroud 54 and intothe bores 45 of the socket Vformations 43. Each lin restraining screw 48 is then adjusted topro- Y ject the inner endY thereof into the socket 28 in the associated lin journal memberl27 but isrnot tightenedfat this time.V Fin incidence is thenjadjusted by` tightening the yElin incidence set screws 53 on one .iside while loosening the set screwl 53 on the'other side of the iin untilV the vlin incidence is'y appropriately adjusted." In one speciiicernv I bodiment, the length of the iin incidence set-screws andk j if the dimensioning of the components cooperating there# Y with issuehas topermitladjustment of the iin from approximately `plus one-thirddegree Yto. minus .one-third degree, Y although by selection of diierent sizes of setl screws, considerably greater ranges of `incidence adjustment, y'for example, upto approximatelyplus lor minus two degrees maybe provided. VAfterthe incidence has been set, the' incidence set Vscrews 53 and Vthe n restraining screws 48 are all securely tightened andthe assemblyfis completed; y Y 15 VWhile but one preferred example of lthe presentinventionhas beenl particularly shown/and described, itis apparentrthat various modifications maybe made 'therein 'i within the 'spirit andjscope of the invention,l and it is;V

desired, thereforegthat only fsuch limitations be Yplaced l on the invention'as Vareimprosecl bythe priorzartjand setk forth'in the'appended claims. l i What is claimednis:V

1. In arocket having'an axiallyelongated-rocket body portion, a iin assemblycomprising Aa plurality of fins .25V

adapted Vto be supported in radially outwardly projecting relation surrounding said body portion,feach of said iins including a. root end Vportion having a cylindrical stub member projecting' radially inwardly toward the axis of said body portion, supporting structure to'.V beimountedom the rocket body'portion in surrounding relation thereto including Aa pluralityl ofcir'cumferentially spaced n Ymounts having radially outwardly opening socketsforl receiving said stub members of said fins and supporting the tins for rotation about radial axes` of said body' por-` 'tion and at least one projection extending radiallyaoutf Y wardly. and -located eccentrically relativertorthe axis of each socket, Vsaidriin mounts having adjustable locking means for releasablylocking said stubs in'said sockets,

and an adjustable memberfspaced from the stubk axis vandV carried by the root portion of teach finv projectable into j VbearingV engagement with `each of said projections for s e-V curing each of said nsrin selected angular positions aboutf their stub axes. a f

Y Y s V2. In a rocket of` the typehaving a cylindrical rocket motor'case terminating in a rearwardly',openingY rocket radially outwardly projecting V- relation surrounding fsaid nozzle, VeachV of saidns including afroot en'd'portion "having a vcylindrical stub member Vprojecting inwardlyfalong aradial axisof the rocketmotor caseuanda pair`VV of inwardly'opening socketsspaced fore Vandaft ,from

said stubV member, supporting structureto .be mounted on the rocket motorcase Vin concentric surrounding relationV including a plurality of circumferentially spaced n l mounts-having radially outwardlyuopening sockets'for receiving said stub members of said lins, said'r nmounts,

having adjustable locking means' for releasably locking said stubsY in the. socketsof the iin mounts, said iin mounts 7 including stationary members projectingradially loutwardly therefromintorsaid sockets in said root portion,

and adjustable means in the root end portion of each n 1 spaced from the stub axis and Vbearing againstV said .star tionary members for securing each of said iins in selected angular positions about 4,theirstub axes.

-3.In a rocket .of thertypehavinga Vcylindrical rocket I motor case terminating in arearrwardly' opening rocket,V -motor nozzle at the trailingend thereof, a iin assembly comprising a plurality-of nsfadapted togrbe supported in radially outwardly projecting relation surrounding saidV Y Y nozzle, each of said tins including a root endk plate por' Y tion having' a fore landaft axisjan'dl-having acylindricalk n stub Vmember Yprojecting Yinwardly along a radius of "a rocket motor case and atleast one inwardly'fopening socketspacedralong the fore and aftv axis from said stub member, a ring assembly supporting structure including a pair of segmental annular ring members to be mounted on the rocket motor case and nozzle in concentric surrounding relation thereto, means for securing said ring members to the rocket motor case and nozzle, said supporting structure including a plurality of circumferential- Y ly spaced fin mounts extending between said ring members along axes paralleling the motor case axis each having an annular socket wall surrounding a radially outwardly opening socket for receiving and rotatably supporting a stub member of one of said ns, each of said annular socket Walls having adjustable locking means for releasably locking said stub members in the socket of the mount, said iin mounts each including at least one radially outwardly projecting stationary lug member located eccentrically of the axis of the socket therein to extend into a socket in said root end plate portion, and adjustable set screw members in the root end plate portion of each n projecting into the socket in said root end plate portion to bear against opposite sides of the stationary lug disposed therein along axes generally transverse to the motor case axis for varying the angular positions of said ns about the stub axes to effect adjustment of n incidence setting.

4. In a rocket of the type having a cylindrical rocket motor case terminating in a rearwardly opening rocket motor nozzle at the trailing end thereof, a iin assembly comprising a plurality of fins adapted to be supported in radially outwardly projecting relation surrounding said nozzle, each of said fins including a root end plate portion having a cylindrical stub member projecting inwardly along a radius of a rocket motor case and a pair of inwardly opening sockets spaced fore and aft from said stub member, a ring assembly supporting structure including a pair of segmental annular ring members to be mounted on the rocket motor case and nozzle in concentric surrounding relation thereto, means for securing said ring members to the rocket motor case and nozzle, said supporting structure including a plurality of circumferentially spaced n mounts extending between said ring members along axes paralleling the motor case axis each having an annular socket wall surrounding a radially outwardly opening socket for receiving and rotatably supporting a stub member of one of said fins, each of said annular socket walls having adjustable locking means for releasably locking said stub members in the socket of the mount, said n mounts each including a pair of radially outwardly projecting stationary lug members located eccentrically of the axis of the socket therein in diametrically opposite relation along axes paralleling the motor case axis to extend into the sockets in said root end plate portion of one of said fins, and a pair of adjustable set screw members threaded in the root end plate portion of each fin adjacent and projectable into each of the sockets in said root end plate portion to bear against opposite sides of the stationary lug lying in their associated socket, said adjustable set screw members being adjustable along axes generally transverse to the motor case axis for varying the angular positions of said tins about the stub axes through selected ranges to permit adjustment of tin incidence setting.

5. In a rocket, the combination recited in claim l wherein said adjustable locking means comprises a n restraining screw threaded into said fin mount for movement along an axis inclined inwardly toward the motor case axis at an acute angle to the axis of the socket in the associated tin mount and projectable into said socket, and the stub member of each of said fins having a locking recess in a side thereof for receiving an inner end portion of the fin restraining screw and having a locking surface inclined to the axis of the stub member to engage the inner end portion of the iin restraining screw and prevent withdrawal of the stub member from the socket therefor in said fin mounts.

6. In a rocket, the combination recited in claim 3 wherein said adjustable locking means comprises a iin restraining screw threaded into said fin mount for movement along an axis inclined inwardly toward the motor case axis at an acute angle to the axis of the socket in the associated fin mount and projectable into said socket, and the stub member of each of said fins having a locking recess in a side thereof for receiving an inner end portion of the iin restraining screw and having a locking surface inclined to the axis of the stub member to engage the inner end portion of the iin restraining screw and prevent withdrawal of the stub member from the socket therefor in said n mounts.

7. In a rocket, the combination recited in claim 4 wherein said adjustable locking means comprises a iin restraining screw threaded into said iin mount for movement along an axis inclined inwardly toward the motor case axis at an acute angle to the axis of the socket in the associated n mount and projectable into said socket, and the stub member of each of said fins having a locking recess in a side thereof for receiving an inner end portion of the n restraining screw and having a locking surface inclined to the axis of the stub member tot engage the inner end portion of the fin restraining screw and prevent withdrawal of the stub member from the socket therefor in said n mounts.

8. In a rocket of the type having a cylindrical rocket motor case terminating in a rearwardly opening rocket motor nozzle at the trailing end thereof, a iin assembly comprising a plurality of fins adapted to be supported in radially outwardly projecting relation surrounding said nozzle, each of said fins including a root end plate portion having a cylindrical stub member projecting inwardly along a radius of a rocket motor case and a pair of inwardly opening sockets spaced fore and aft from said stub member, a ring assembly supporting structure including a pair of segmental annular ring members to be mounted on the rocket motor case and nozzle in concentric surrounding relation thereto, means for securing said ring members t`o the rocket motor case and nozzle, said supporting structure including a plurality of circumferentially spaced iin mounts extending between said ring members along axes paralleling the motor case axis each having an annular socket wall surrounding a radially outwardly opening socket for receiving and rotatably supporting a stub member of one of said fins, each of said annular socket walls having adjustable locking means for releasably locking said stub members in the socket of the mount,said fin mounts each including a pair of radially outwardly projecting removable torque pins having terminal flats on the ends thereof located eccentrically of the axis of the socket therein in diametrically opposite relation along axes paralleling the motor case axis to extend into the sockets in said root end plate portion of one of said tins, and a pair of adjustable set screw members threaded in the root end plate portion of each iin adjacent and projectable into each of the sockets in said root end plate portion to bear against the flats of the torque pin lying in their associated socket, said adjustable set screw members being adjustable along axes generally transverse to the motor case axis for varying the angular positions of said tins about the stub axes through selected ranges to permit adjustment of tin incidence setting.

9. In a rocket having an axially elongated rocket body portion, a iin assembly comprising a plurality of fins adapted to be supported in outwardly projecting relation surrounding said body portion, each of said fins including a root end portion having an inwardly projecting cylindrical stub member, supporting structure to be mounted on the rocket body portion in surrounding relation thereto including a plurality of circumferentially spaced iin mounts having outwardly opening sockets for receiving said stub members of said tins and supporting the tins for rotational movement and at least one outwardly extending projection located eccentrically relative to the axis of each socket, said n mounts having adjustable 

1. IN A ROCKET HAVING AN AXIALLY ELONGATED ROCKET BODY PORTION, A FIN ASSEMBLY COMPRISING A PLURALITY OF FINS ADAPTED TO BE SUPPORTED IN RADIALLY OUTWARDLY PROJECTING RELATION SURROUNDING SAID BODY PORTION, EACH OF SAID FINS INCLUDING A ROOT END PORTION HAVING A CYLINDRICAL STUB MEMBER PROJECTING RADIALLY INWARDLY TOWARD THE AXIS OF SAID BODY PORTION, SUPPORTING STRUCTURE TO BE MOUNTED ON THE ROCKET BODY PORTION IN SURROUNDING RELATION THERETO INCLUDING A PLURALITY OF CIRCUMFERENTIALLY SPACED FIN MOUNTS HAVING RADIALLY OUTWARDLY OPENING SOCKETS FOR RECEIVING SAID STUB MEMBERS OF SAID FINS AND SUPPORTING THE FINS FOR ROTATION ABOUT RADIAL AXES OF SAID BODY PORTION AND AT LEAST ONE PROJECTION EXTENDING RADIALLY OUT- 